Range finder



June 4, 1946.

F. M. E. HOLMES ET AL 2,401,686

RANGE FINDER Filed March 15, 1943 5 Sheets-Sheet 1 3.9 37 FIG. 1. 4.2

I E S 7mm 3?X 53 FIG. 2 I 41 H 40 21 "6b 4 LIGHT DEV/ATOR I 25 V fig F163.

I v I v 41 FREDERICK M.E.HOLMES JOSEPH MIHALYI I INVENTORS BY dam A TTORNE Y Jun 4,1946. F. M, E. HOLMES'ETAL 2,401,686

RANGE FINDER Filed March 13, 1943 5 Sheets-Sheet 2 3Q36 LIGHT DEV/ATOR 67 L "1 f W50 $51 t? 51 5E Q1? LIGHT #5 DEV/ATOR FIG. 6,. 5 I I fi 85 56 was 84; fizz e 2J v FREDERICK M.E. HOLMES JOSEPH MIHALYI INVENTORS A TTORNE Y June 1946. F. M. EpHOLMES ET AL RANGE FINDER 5 Sheets-Sheet 3 Filed March 13, 1943 w 1 fax 5?. a 7 m 1 F-%w J FREDERICK MEHOLMES' JOSEPH MIHALYI INVENTORS W.m BY

ATTORNEY FIG. 7A.

June 4-, 1946. F. M. E. OLMES ET AL 2, 01,686

RANGE FINDER Filed March 13, 1943 5 Sheets-Sheet 4 FIG. 11.

mmmm I I E B FREDERICK MEHOLMES JOSEPH MIHALY! ZNVENTORS ATTORNEY June 1946- F. M. EHQLMES ET AL ,2, l,86

RANGE FINDER Filed March 13, 1943 5 Sheets-Sheet 5 FIG. 18.

FIG. 19.

FREDERICK MEH OLMES JOSEPH M'IHALYL INVENTORS W. W BY ATTORNEYS Patented June 4, 1946 UNITED STATES PATENT OFFICE RANGE FINDER Frederick M. E. Holmes and Joseph Mihalyi, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N.

New Jersey a corporation of Application March 13, 1943, Serial No. 479,098

8 Claims. 1 This invention relates to range finders. This is Case H of a series of applications relating to this samesubject. The series includes the following:

Inventors Mount for optical ele- 461,584 Oct. 10,1942 Millalyi.

ments. Range finder construction.

Range finders-asc A Range fihders-0as B Range finders-Case O Range ers-0ase D Range finders-Gase E Range finders-Case Ft. Range finders-Oase G. Range finders-Case I Do. M ihal MacNeille. Mihalyi, Tuttlc. Mihalyi.

Do. Mihalyi, MacNeille.

MacNeillc, Holmes. Mihalvi, MacNeille. Mihalyl.

MacNeillc. MacNeille, Mihalyi. lvlacNeille. MacNeille, Mihalyi. M acNeille rs-Case N. 491, 955 June Range finders-0ase 0. 4 Range finders-Case P Range finders-Case T- The present Case H relates to an invention which constitutes any maladjustment therein. cating elements they are viewed by the main observer or by an auxiliary observer.

Thus, in a range finderhaving an autocollimating arrangement involving an element light beam traversing the optical system of the range finder,

by the main observer finder optical system While ranging. A third embodiment which is a species of the Thus each lens serves to collimate the light from the other element connecwhich elevation of one detail shown in Fig. is a plan view of the arrangement shown in Fig. 4,

Fig. 6 is a plan view of an embodiment or the invention differing slightly from that shown in Fig. 2,

Fig. 1 is a plan view of another embodiment similar to Fig. 6, Fig. 7A showing the field of view of the auxiliary observer,

Fig. 8 shows a range finder differing from Fig. l by the use of a coincidence line and fiducial mark,

.Fig. 9 shows an embodiment of the invention slightly different from Fig. 8,

Fig. 10 is a plan view of a preferred embodiment of the invention applied to coincidence range finders,

Fig. 11 is an shown in Fig. 10,

Fig. 12 shows the view through the eyepiece of the range finder shown in Figs. 10 and 11,

Fig. 13 is a plan view of an embodiment different slightly from that shown in Fig; 10,

Figs.14 and 15 show one detail of Fig. 13 enlarged,

Fig. 16 illustrates an embodiment slightly'difierent from that shown in Fig. 15,

Fig. 1'1 shows an embodiment of the invention which differs from Fig. 13 by the use of coincidence lines,

Fig. 18 is an enlarged view of one detail of elevation of the arrangement Fig. 17,

Fig. 19 is a plan view of a range finder incorporating the optical system shown in Fig. 1'7.

In Figs. 1, 2 and 3, light from an object being ranged is reflected by penta prisms 21 to crossed reflectors 22 and 23 and thence through an objective' 24 forming images in a comparison plane 25 to be viewed by the eye 26 of an observer, who adjusts the images by means of a light deviator 36 until they are in coincidence. According to the invention there are engraved on the comparison plane, an'index 34 and a scale 31' which are respectively illuminated by lamp 32 and prism 33 and lamp 35 and prism 36. Light from these adjustment ooindicant elements 34 and '31 is collimated by the objective 24 and is reflected respectively by prisms 22 and 23 to the penta prisms 2|. These element light beams are then picked up by small penta prisms 38 and 39 and directed toward a prism 40' whose surfaces are silvered'to reflect both beams upward through a lens 4| and into focus on an image plane 42, forming images 34 and 31' which may be viewed by the eye 43 of an observer.

The main observer whose eye is shown in 26 adjusts the light deviator 30 until the object images are in coincidence at which time the observer whose eye is shown at 43 reads the range as indicated by the element images 34 and 31'.

Figs. 4 and 5 illustrate a stereo range finder in which light from the object being ranged is received by penta prisms 50 and is focused by objectives 5| in comparison planes 52 which carry stereo reticle marks 53. The images and the reticle marks are viewed stereoscopically through prisms 54 and eyepieces 55 by the right and left' eyes 56 of an observer. A light deviator 51 is adjusted until the apparent object distance is the same as the apparent mark distance. According to the invention, one of the image planes is provided with an index 62 illuminated by a lamp 60 and prism GI and the other image plane is provided with a scale 66 illuminated by a lamp 64 and a prism 65. Light from these two adjustment coindicant elements 61 and 66 is collimated by the objectives 5| and directed by the penta prisms 52 into small auxiliary penta prisms 63 and 61 respectively which in turn direct the beams toward reflectors 68 and upward through an objective 6i! into focus forming images 62' and 66' in a range indicating plane 16 to be viewed by the eye 11 of an observer.

In Fig. 6 there is shown a slight variation of the arrangement shown in Fig. 1 since the adjustment coindicant elements are not located in the comparison planes, but in the optical equivalent thereof. In Fig. 6 light from the object being ranged is directed by penta prism 15 to crossed reflectors 16 and is focused by an objective 11 in coplanar comparison planes to be viewed through an eyepiece 18 by the eye 19 of an observer. Coincidence is obtained by adjusting a light deviator 80. Since anything which affects one of the object beams between its reflector 16 and the eye 19, similarly affects the other object beam, the element light beams need only traverse those arts of the range finder system which are optically ahead of the reflectors 16, including the reflectors 16 themselves. Light from a lamp 8| illuminates adjustment coindicant elements on a transparent element 82 andthis light is collimated by a lens 83 so that the element beams are reflected respectively by the backs of the reflectors 16 toward the penta prisms 15. These element beams are then reflected by auxiliary penta prisms 84 toward reflectors 85 and upward through a lens 86 to an image plane 81 to be viewed by the eye 88 of an auxiliary observer. The elements 85, 86, 81 and B8 correspond exactly to elements 40, 4|, 42 and 43 of Figs. 1 to 3.

Fig. 7 is similar to Fig. 6 but differs in a few details. Light from the object being ranged is reflected by prisms 90 through objective 9| toward crossed reflectors 92; and into focus on an image plane 93 which is viewed through an eyepiece 34 by the eye 95 of an observer. Coincidence is obtained by adjusting a light deviator 96. Light from a lamp 91 illuminates a scale and index engraved on trans-parent element 98 which is located on the opposite side of the reflectors 92 from the image plane 93, and at the same distance therefrom. Thus, light from the adjustment coindicant elements is collimated by the objectives 9| and is directed by small penta prisms 99 and I00 which are facing in the same instead of opposite directions, through an objective I01 which brings them to focus in an image plane 102 forming images I04 and as best seen in Fig. 7A, to be viewed by the eye 103 of an observer. v The advantages of this system over'that shown in Figs. 1 and 6, lie in the elimination of the reflectors 40'and 85 respectively. I Fig. 8 is similar to Fig. 1, but employ of the scale 31 and index 34, a c'oincidence line and fiducial mark. Light from the lamp 35 passes upward through a disk H0 on which is engraved a coincidence line in the form of a spiral Ill. Actually this spiral is positioned in the focal plane of the objective 24, by having the disk'up close to the element 25 and the prism .36behind the element 25, but it is shown sepain place and the range may be 9 in which-a rotatable tion, light from lamps and fiducial marks, is brought to focus forming images III and H3 in the image plane 42.

of the coincidence line falls exactly between the fiducial spots I I3. For convenience, a scale H2 is engraved adjacent to the coincidence spiral III. The image H2 of this scale employs the fiducial marks II3 as an index read directly by the observer whose eye is shown at 43.

A somewhat similar arrangement is shown in disk II? carries a circle I I8 which acts as a fiducial mark and a spiral These elements prisms I I6.

are illuminated by lamps I I5 and When the observer Whose eye is obtains coincidence of the object corresponding to the fiducial mark H8 and coincidence line I I9, are in register. At this time an observer whose eye is shown at I22 reads the range from a scale I engraved on the disk H1 and an index IZI. The eyes and I22 may be the right and left eyes of the same observer and eye is shown at 43 may operate the disk II1 continually, while ranging, to maintain register of the images 8' and H9. In this way, the main observer may read the range as soon as he obtains coincidence.

Figs. 10 to 19 illustrate embodiments of the cooperating adjustment coindicant elements. In Figs. 10, 11 and 12, light from the object being ranged is received by penta prisms I25 and is reflected by crossed reflectors I26 through an objective I21 into focus in an image plane I28 to be viewed through an eyepiece I29 by the eye I38 of an observer. These object beams form images I3I as best seen in Fig. 12. Coincidence is obtained by adjusting a light deviator I4I. According to the inven- I as reflected by prisms I36 passes adjustment coinolicant elements, which themselves are not shown but Whose images appear as I39 and I4!) in Fig. 12. These adjustment coindicant elements are engraved on lenses I31 or attached thereto 50 as to be substantially at the nodal planes of each lens. These lenses are of equa1 focal length and are separated by a distance equal to the focal length So that the light from each adjustment coindicant element is collimated by the other lens. The resulting element beams are picked up by small penta prisms I38 and directed into the range finder optical system, automatically to form images I39 and I48 in the comparison planes I28. The purpose of this nodal-plane-focal-plane system is to prevent maladjustment of this auxiliary system having any effect on the reading. If one of the lenses together with its adjustment coindicant element is moved slightly sideways so that its image appearing in the comparison plane I28 moves slightly sideways, this same movement shifts the element beam coming from the other adjustment coindicant element by an equivalent amount so that its image moves equallyand reading of the scale I40 and index I39 remains unchanged, although both images are moved to one side slightly.

Figs. 13 to 16 are similar to Fig. 10 but two objectives I45 are used in place of the single objective I21 and the comparison planes are in a somewhat more complicated prism assembly con sisting of cross prism I46 and I41 on the latter of which is cemented a rhomb I48 to receive the incoming beam at the same level as the beam I46. Light from these crossed prisms I46 is reflected to 30 right angle prisms I 49 and I59 whose interface I5I consists of two portions one of which, I53, is clear and the other of which, I52, is reflecting. As shown by the ray I6! in Fig. 15 light from the prism I46 is reflected down tothe reflecting surface I52 and thence upward to the eye I63 of an observer. As shown by the ray I62 on the other hand, light from the prism I41 is reflected up by the prism I56 and through thetransparent area, I53 to the eye I63. Thi arrangement permits the observer whose eyeis shown at I63 to see both the object images which are to be adjusted for coincidence and the scale and index.

An alternative arrangement shown in Fig. 16 has the scale and index so positioned that the element beams do not reach the eye I63. The light from the scale as shown by the ray I65 passes downward through the transparent area I 53 to the eye I61 of an auxiliary observer and similarly as shown by the ray I66 light from the index is reflected from the bottom of the reflecting surface I52 downward to this eye I61.

Figs. 1'7 to 19 show a similar arrangement in which a fiducial mark and coincidence line replace the scale and index of Fig. 13. The fiducial mark is practically identical to the index mark used in Fig. 13. The coincidence line is in the form of a spiral I1I carried on a disk I 10 which is rotated in one of the nodal planes. As shown in Fig. 19 this rotation is provided by a gear I The mark appears at I6I in Fig. 17 and the image of the coincidence line ap- To operate the device the observer views the two object images and obtains coincidence by adjusting the light deviator I II. the same time, he rotates the knob I81 until images I6I and HI the are in coincidence, at which Thus this Case H is equally applicable to range correction setting systems as well as to the simpler forms of autocollimators.

Having thus described various preferred embodiments of our invention, We wish to point out that it is not limited to these structures but is of the scope of the appended claims.

What we claim and desire to secure by Letters Patent of the United States is:

l. A range finder of the type having two spaced viewing points at which substantially collimated beams of light are received from the object being ranged, an optical system including at least one objective for directing the two beams into focus forming images in comparison planes, one portion of the system operating only on one of the beams, a different portion operating only on the other beam and a ranging adjuster, said range finder being characterized by a pair of adjustment coindicant elements, and; means for projecting through the exact optical equivalent of the two portions, light from each of the two elements respectively, into focus in a single plane forming images of the elements coindicantly adjacent to one another, said ranging adjuster moving one of the element images relative to the other and one of the object images relative to the other by exactly the same amounts.

2. A range finder according to claim 1 in which the ranging adjuster is a light deviating means in one of said portions for deviating simultaneously the light from the object being ranged and the light from one of the elements.

3. A range finder according to claim 1 and of the coincidence type, in which said single plane and both comparison planes are all coplanar and an eyepiece is provided for viewing the object images and the element images.

4. A range finder according to claim 1 in which the elements are at least optically in the comparison planes and reflecting means are provided in each of said two portions for directing light from the elements to one side of the optical system and in which means are included for receiving this light and focusing both beams into said the coincidence type in single plane which is outside said optical system. 5. A range finder according to claim 1 in which said elements are a scale and an index therefor. 6. A range finder according to claim 1 in which said elements are a fiducial line and a coincidence line cooperating therewith and carried by a movable member.

'7. A range finder according to claim 1 and of the stereo type in which said elements are at least optically in the comparison planes and reflecting means are provided in each of said two portions for directing light from the images to one side of the optical system and in which means are included for receiving this light and focusing both beams into said single plane which is outside said optical system.

8. A range finder according to claim 1 and of which the elementsare attached to lenses of equal focal length and each element is in the nodal plane of its lens and in the focal plane of the other lens whereby collimated beams are formed by light from the elements through the lenses and in which reflectors are included in said portions for receiving the latter beams and directing them through the portions to said single plane. V

FREDERICK M. E. HOLMES.

JOSEPH MIHALYI. 

